Method and apparatus for requesting point-to-point protocol (PPP) instances from a packet data services network

ABSTRACT

A method and apparatus for requesting PPP instances from a packet data services network includes a mobile station configured to send an origination message to a packet data service node (PDSN) at which it has arrived upon leaving the vicinity of another PDSN. The message informs the new PDSN of the new location of the mobile station and indicates both the number of dormant PPP instances associated with the mobile station and a service reference identifier for each such PPP instance. A flag within the message may be used to indicate whether the PPP instances are dormant (i.e., whether the mobile station is engaged in a call).

CLAIM OF PRIORITY UNDER 35 U.S.C. §120

The present Application for Patent is a continuation of patentapplication Ser. No. 09/477,278 entitled “Method and Apparatus forRequesting Point-To-Point Protocol (PPP) Instances From A Packet DataServices Network” filed Jan. 4, 2000, now U.S. Pat. No. 7,190,687, andassigned to the assignee hereof and hereby expressly incorporated byreference herein.

BACKGROUND

1. Field

The present invention pertains generally to the field of communications,and more specifically to requesting point-to-point protocol (PPP)instances from a packet data services network.

2. Background

With the increasing popularity of both wireless communications andInternet applications, a market has arisen for products and servicesthat combine the two. As a result, various methods and systems are underdevelopment to provide wireless Internet services that would allow auser of a wireless telephone or terminal to access email, web pages, andother network resources. Because information on the Internet isorganized into discrete “packets” of data, these services are oftenreferred to as “packet data services.”

Among the different types of wireless communication systems to be usedto provide wireless packet data services are code division multipleaccess (CDMA) systems. The use of CDMA modulation techniques is one ofseveral techniques for facilitating communications in which a largenumber of system users are present. The framing and transmission ofInternet Protocol (IP) data through a CDMA wireless network is wellknown in the art and has been described in TIA/EIA/IS-707-A, entitled“DATA SERVICE OPTIONS FOR SPREAD SPECTRUM SYSTEMS,” hereinafter referredto as IS-707.

Other multiple access communication system techniques, such as timedivision multiple access (TDMA), frequency division multiple access(FDMA), and AM modulation schemes such as amplitude companded singlesideband (ACSSB) modulation are known in the art. These techniques havebeen standardized to facilitate interoperation between equipmentmanufactured by different companies. CDMA communications systems havebeen standardized in the United States in Telecommunications IndustryAssociation TIA/EIA/IS-95-B, entitled “MOBILE STATION-BASE STATIONCOMPATIBILITY STANDARD FOR DUAL-MODE WIDEBAND SPREAD SPECTRUM CELLULARSYSTEMS,” hereinafter referred to as IS-95.

The International Telecommunications Union recently requested thesubmission of proposed methods for providing high-rate data andhigh-quality speech services over wireless communication channels. Afirst of these proposals was issued by the Telecommunications IndustryAssociation, entitled “The cdma2000 ITU-R RTT Candidate Submission,” andhereinafter referred to as cdma2000. A second of these proposals wasissued by the European Telecommunications Standards Institute (ETSI),entitled “The ETSI UMTS Terrestrial Radio Access (UTRA) ITU-R RTTCandidate Submission,” also known as “wideband CDMA,” and hereinafterreferred to as W-CDMA. A third proposal was submitted by U.S. TG 8/1,entitled “The UWC-136 Candidate Submission,” hereinafter referred to asEDGE. The contents of these submissions are public record and are wellknown in the art.

Several standards have been developed by the Internet Engineering TaskForce (IETF) to facilitate mobile packet data services using theInternet. Mobile IP is one such standard, and was designed to allow adevice having an IP address to exchange data with the Internet whilephysically travelling throughout a network (or networks). Mobile IP isdescribed in detail in IETF request for comments (RFC), entitled “IPMobility Support,” and incorporated by reference.

Several other IETF standards set forth techniques referred to in theabove-named references. Point-to-Point Protocol (PPP) is well known inthe art and is described in ETF RFC 1661, entitled “The Point-to-PointProtocol (PPP)” and published in July 1994, hereinafter referred to asPPP. PPP includes a Link Control Protocol (LCP) and several NetworkControl Protocols (NCP) used for establishing and configuring differentnetwork-layer protocols over a PPP link. One such NCP is the InternetProtocol Control Protocol (IPCP), well known in the art and described inIETF RFC 1332, entitled “The PPP Internet Protocol Control Protocol(IPCP),” published in May of 1992, and hereinafter referred to as IPCP.Extensions to the LCP are well known in the art and described in IETFRFC 1570, entitled “PPP LCP Extensions,” published in January 1994, andhereinafter referred to as LCP.

Mobile stations, such as, e.g., cellular or PCS telephones with Internetconnections, typically transmit packet data over a network byestablishing a PPP connection (or PPP instance, or PPP session), with apacket data service node (PDSN). The mobile station sends packets acrossan RF interface such as, e.g., a CDMA interface, to a base station orpacket control function. The base station or packet control functionestablishes the PPP instance with the PDSN. More than one such PPPinstance may be established contemporaneously (e.g., if a phone and alaptop each require a connection). Data packets are routed from the PDSNto a home agent (HA) via an IP network in accordance with the particularPPP instance. Packets being sent to the mobile station are routed fromthe HA via the IP network to the PDSN, from the PDSN to the base stationor packet control function via the PPP instance, and from the basestation or packet control function to the mobile station via the RFinterface.

When a mobile station leaves the vicinity of a PDSN and enters thevicinity of another PDSN, the mobile station sends an originationmessage. If the mobile station is engaged in a data call, theorigination message requests reconnection or establishment of theassociated PPP instance. Otherwise, the origination message informs thenew PDSN of the new location of the mobile station. Nevertheless, anydata packets being sent to the mobile station will be routed to the oldPDSN because the mobile station does not have a PPP instance establishedwith the new PDSN. Accordingly, packets destined for the mobile stationwill become lost. Thus, there is a need for a method of informing a PDSNof the number and identities of PPP instances to be established for anewly arriving mobile station.

SUMMARY OF THE INVENTION

The present invention is directed to a method of informing a PDSN of thenumber and identities of PPP instances to be established for a newlyarriving mobile station. Accordingly, in one aspect of the invention, amethod of informing a packet data services network of dormant networkconnections associated with a mobile station when the mobile stationmoves from a first infrastructure element of the packet data servicesnetwork to a second infrastructure element of the packet data servicesnetwork is provided. The method advantageously includes the step oftransmitting from the mobile station a message including a number ofdormant network connections associated with the mobile station and alist of identifiers associated with the dormant network connections.

In another aspect of the invention, a mobile station configured toinform a packet data services network of dormant network connectionsassociated with the mobile station when the mobile station moves from afirst infrastructure element of the packet data services network to asecond infrastructure element of the packet data services network isprovided. The mobile station advantageously includes an antenna; aprocessor coupled to the antenna; and a processor-readable mediumaccessible by the processor and containing a set of instructionsexecutable by the processor to modulate and transmit from the mobilestation a message including a number of dormant network connectionsassociated with the mobile station and a list of identifiers associatedwith the dormant network connections.

In another aspect of the invention, a mobile station configured toinform a packet data services network of dormant network connectionsassociated with the mobile station when the mobile station moves from afirst infrastructure element of the packet data services network to asecond infrastructure element of the packet data services network isprovided. The mobile station advantageously includes a device configuredto transmit from the mobile station a message including a number ofdormant network connections associated with the mobile station and alist of identifiers associated with the dormant network connections.

In another aspect of the invention, a mobile station configured toinform a packet data services network of dormant network connectionsassociated with the mobile station when the mobile station moves from afirst infrastructure element of the packet data services network to asecond infrastructure element of the packet data services network isprovided. The mobile station advantageously includes means fortransmitting from the mobile station a message including a number ofdormant network connections associated with the mobile station and alist of identifiers associated with the dormant network connections.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a wireless communication system configuredto perform packet data networking.

FIG. 2 is a block diagram of a packet data service node (PDSN).

FIG. 3A is a block diagram of two PDSNs coupled to radio access networks(RANs) wherein a mobile station (MS) has traveled to the vicinity of thesecond PDSN without establishing new PPP instances, FIG. 3B is a blockdiagram of two PDSNs coupled to RANs wherein an MS has traveled to thevicinity of the second PDSN and established new PPP instances, and FIG.3C is a block diagram of an MS traveling from the vicinity of the firstPDSN to the vicinity of the second PDSN informing the second PDSN of thenumber and identities of PPP instances to be established.

FIG. 4 is a flow chart illustrating method steps performed by a mobilestation to inform a PDSN of the number and identities of PPP instancesrequired to be established.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In one embodiment a wireless communication system 100 for performingpacket data networking includes the elements shown in FIG. 1. A mobilestation (MS) 102 is advantageously capable of performing one or morewireless packet data protocols. In one embodiment the MS 102 is awireless telephone running an IP-based Web-browser application. In oneembodiment the MS 102 is not connected to any external device, such as alaptop. In an alternative embodiment, the MS 102 is a wireless telephonethat is connected to an external device, wherein a protocol option isused that is equivalent to the Network Layer R_(m) Interface ProtocolOption described in IS-707. In another alternative embodiment, the MS102 is a wireless telephone that is connected to an external device,wherein a protocol option is used that is equivalent to the Relay LayerR_(m) Interface Protocol Option described in the aforementioned IS-707.

In a particular embodiment, the MS 102 communicates with an InternetProtocol (IP) network 104 via wireless communications with a radioaccess network (RAN) 106. The MS 102 generates IP packets for the IPnetwork 104 and encapsulates the IP packets into frames destined for aPacket Data Serving Node (PDSN) 108. In one embodiment the IP packetsare encapsulated using a point-to-point protocol (PPP) and the resultantPPP byte stream is transmitted through a code division multiple access(CDMA) network using a Radio Link Protocol (RLP).

The MS 102 sends the frames to the RAN 106 by modulating andtransmitting the frames through an antenna 110. The frames are receivedby the RAN 106 through an antenna 112. The RAN 106 sends the receivedframes to the PDSN 108, at which the IP packets are extracted from thereceived frames. After the PDSN 108 extracts the IP packets from thedata stream, the PDSN 108 routes the IP packets to the IP network 104.Conversely, the PDSN 108 can send encapsulated frames through the RAN106 to the MS 102.

In one embodiment the PDSN 108 is coupled to a Remote AuthenticationDial In User Service (RADIUS) server 114 for authenticating the MS 102.The PDSN 108 is also coupled to a Home Agent (HA) 116 for supporting theMobile IP protocol. The HA 116 advantageously includes entities capableof authenticating the MS 102 and for granting the MS 102 the use of anIP address when Mobile IP is to be used. One skilled in the art wouldrecognize that the RADIUS server 114 could be replaced with a DIAMETERserver or any other Authentication, Authorization, and Accounting (AAA)server.

In one embodiment the MS 102 generates IP packets, and the PDSN 108 iscoupled to the IP network 104. One skilled in the art would recognizethat alternate embodiments could use formats and protocols other thanIP. In addition, the PDSN 108 may be coupled to a network capable ofemploying protocols other than IP.

In one embodiment the RAN 106 and the MS 102 communicate with each otherusing wireless spread spectrum techniques. In a particular embodiment,the data is wirelessly transmitted using CDMA multiple accesstechniques, as described in U.S. Pat. Nos. 5,103,459 and 4,901,307,which are assigned to the assignee of the present invention and fullyincorporated herein by reference. One skilled in the art would recognizethat the methods and techniques described herein may be used inconjunction with several alternate modulation techniques, includingTDMA, cdma2000, W-CDMA, and EDGE.

In one embodiment the MS 102 has the ability to perform RLP, PPP,Challenge Handshake Authentication Protocol (CHAP), and Mobile IP. In aparticular embodiment, the RAN 106 communicates with the MS 102 usingRLP. In one embodiment the PDSN 108 supports PPP functionality,including Link Control Protocol (LCP), CHAP, and the PPP InternetProtocol Control Protocol (IPCP). In one embodiment the PDSN 108, RADIUSserver 114, and HA 116 are physically located in different physicaldevices. In an alternate embodiment, one or more of these entities canbe located in the same physical device.

In one embodiment PDSN 200 includes a control processor 202, a networkpacket switch 204, an IP network interface 206, and an RAN interface208, as shown in FIG. 2. The IP network interface 206 is coupled to thenetwork packet switch 204. The network packet switch 204 is coupled tothe control processor 202 and to the RAN interface 208. The RANinterface 208 receives data packets from an RAN (not shown). The RANinterface 208 receives the packets over a physical interface. In oneembodiment the physical interface is T3, a standard digitaltelecommunications interface that has a forty-five Mbps transfer rate.The physical T3 interface could be replaced with a T1 interface, anEthernet interface, or any other physical interface used for datanetworking.

The RAN interface 208 delivers the received packets to the networkpacket switch 204. In an exemplary embodiment, the connection betweenthe network packet switch 204 and the RAN interface 208 comprises amemory bus connection. The connection between the RAN interface 208 andthe network packet switch 204 could be an Ethernet or any other of avariety of communications links that are well known in the art. The RANinterface 208 is also advantageously capable of receiving packets fromthe network packet switch 204 over the same connection and transmittingthe packets to the RAN.

The network packet switch 204 is advantageously a configurable switchthat is capable of routing packets between a variety of interfaces. Inone embodiment the network packet switch 204 is configured such that allpackets received from the RAN interface 208 and the IP network interface206 are routed to the control processor 202. In an alternate embodiment,the network packet switch 204 is configured such that a subset ofreceived frames from the RAN interface 208 are delivered to the IPnetwork interface 206 and a remaining subset of received frames from theRAN interface 208 are delivered to the control processor 202. In oneembodiment the network packet switch 204 delivers packets to the controlprocessor 202 via a shared memory bus connection. The connection betweenthe RAN interface 208 and the network packet switch 204 could be anEthernet or any other of a variety of well known types of communicationslinks. While the network packet switch 204 is coupled to the RANinterface 208 and the IP network interface 206, one skilled in the artwould appreciate that the network packet switch 204 could be coupled toa smaller or larger number of interfaces. In an embodiment in which thenetwork packet switch 204 is coupled to a single network interface, thatnetwork interface is coupled to both an IP network (not shown) and anRAN. In an alternate embodiment, the network packet switch 204 isincorporated into the control processor 202 such that the controlprocessor 202 communicates directly with the network interface(s).

The control processor 202 exchanges information packets with the RANinterface 208 when a connection with an MS (not shown) is desired. Afterthe control processor 202 receives an information packet indicating thata connection with an MS is desired, the control processor 202 negotiatesa PPP session with the MS. To negotiate the PPP session, the controlprocessor 202 generates PPP frames and sends the PPP frames to the RANinterface 208, and then interprets responses from the MS received fromthe RAN interface 208. The types of frames generated by the controlprocessor 202 include LCP frames, IPCP frames, and CHAP frames. The MSmay be authenticated in accordance with a method described in a U.S.application filed Dec. 3, 1999, Ser. No. not yet assigned, entitledMETHOD AND APPARATUS FOR AUTHENTICATION IN A WIRELESS TELECOMMUNICATIONSSYSTEM, assigned to the assignee of the present invention, and fullyincorporated herein by reference.

The control processor 202 generates packets for exchange with AAAservers (not shown) and Mobile IP Has (also not shown). Additionally,for each established PPP session, the control processor 202 encapsulatesand unencapsulates IP packets. One skilled in the art would recognizethat the control processor 202 may be implemented usingfield-programmable gate arrays (FPGAs), programmable logic devices(PLDs), digital signal processors (DSPs), one or more microprocessors,an application specific integrated circuit (ASIC), or any other devicecapable of performing the PDSN functions described above.

In one embodiment the packets are delivered to the network packet switch204, which, in turn, delivers the packets to the IP network interface206 for delivery to the IP network. The IP network interface 206transmits the packets over a physical interface. In one embodiment thephysical interface is T3, a standard digital telecommunicationsinterface that has a forty-five Mbps transfer rate. The physical T3interface could be replaced with a T1 interface, an Ethernet interface,or any other physical interface used for data networking. The IP networkinterface 206 is also advantageously capable of receiving packets overthe same physical interface.

An MS 300 transmits packet data over an IP network (not shown) byestablishing a PPP instance 302 with a PDSN 304, as shown in FIG. 3A.The MS 300 sends packets across an RF interface such as, e.g., a CDMAinterface, to a packet control function or base station (PCF/BS) 306.The PCF/BS 306 establishes the PPP instance 302 with the PDSN 304.Another PPP instance 308 may be established contemporaneously (e.g., ifa phone and a laptop each require a connection). Data packets are routedfrom the PDSN 304 to an HA (not shown) via an IP network (also notshown) in accordance with the particular PPP instance 302, 308. Packetsbeing sent to the MS 300 are routed from the HA via the IP network tothe PDSN 304, from the PDSN 304 to the PCF/BS 306 via the PPP instance302, 308, and from the PCF/BS 306 to the MS 300 via the RF interface.The PCF/BS 306 includes a PCF/BS table 310. The PCF/BS table 310includes a list of MS identifiers (MS_IDs), service referenceidentifiers (SR_IDs), and RAN-to-PDSN interface (R-P) identifiers (R-PIDs). The PDSN 304 includes a PDSN table 312. The PDSN table 312includes a list of IP addresses, MS_IDs, SR_IDs, and R-P IDs. The PDSN304 may be served by more than one PCF/BS 306, but for simplicity onlyone PCF/IBS 306 is shown coupled to the PDSN 304.

While the MS 300 is idle (i.e., not engaged in a telephone call), the MS300 sends short data bursts as PPP frames. Each such PPP frame includesan SR_ID that identifies which PPP instance 302, 308 is to be thedestination for the PPP frame. As understood by those of skill in theart, the PPP frames encapsulate other protocols. In an exemplaryembodiment, the PPP frame encapsulates a Transport Control Protocol(TCP) frame and identifies the protocol of the encapsulated TCP frame.The TCP frame encapsulates an IP frame and identifies the protocol ofthe IP frame. The IP frame encapsulates a frame such as an RLP frame andalso includes a source header and a destination header. The RLP framemay encapsulate a data frame configured in accordance with, e.g.,IS-95B.

When the MS 300 leaves the vicinity of the PDSN 304 and enters thevicinity of another PDSN 314, the MS 300 sends an origination message.If the MS 300 is engaged in a data call, the call is “handed off” fromthe first PCF/BS 306 to a second PCF/BS 316 coupled to the second PDSN314. An exemplary handoff procedure is described in U.S. Pat. No.5,267,261, which is assigned to the assignee of the present inventionand fully incorporated herein by reference. The MS 300 then sends anorigination message informing the second PDSN 314 of its new locationand requesting the establishment or reconnection of the PPP instanceassociated with the call. Otherwise, the PPP instances 302, 308 are“dormant” and the MS 300 performs a dormant handoff and then sends anorigination message that informs the second PDSN 314 of the new locationof the MS 300. It would be understood by those of skill that the secondPDSN 314 may also be served by more than one PCF/BS 316, but forsimplicity only one PCF/BS 316 is shown coupled to the PDSN 314.Although the network has been informed of the new location of the MS300, the MS 300 requires that two new PPP instances be initiated(because the MS 300 has two dormant SR_IDs pertaining to the dormant PPPservice instances 302, 308). The new PCF/BS 316 and PDSN 314 do not havetables listing SR_IDs or R-P IDs because the two necessary PPP instanceshave not been established. Accordingly, data packets being sent to theMS 300 will be routed to the first PDSN 304 because the MS 300 does nothave a PPP instance established with the new PDSN 314. Hence, packetsdestined for the MS 300 will become lost.

In one embodiment, as shown in FIG. 3B, an MS 318 travels from thevicinity of a first PDSN 320 and associated PCF/BS 322 to the vicinityof a second PDSN 324 and associated PCF/BS 326 and informs the secondPDSN 324 of the number and identities of PPP instances that must beestablished. The first PDSN 320 had established two PPP instances 328,330 between the PDSN 320 and the PCF/BS 322, which were dormant (i.e.,not being used to transmit traffic channel data). The variousestablished connections and addresses are included in the respectivetables 332, 334 for the PDSN 320 and the PCF/BS 322. The number (two)of, and identifiers for, two newly required PPP instances 336, 338 areadvantageously included in the origination message transmitted by the MS318. For simplicity, only one PCF/BS 322, 326 is shown serving eachrespective PDSN 320, 324, but it would be understood that there could bemultiple PCF/BSs serving each PDSN 320, 324. The origination messageadvantageously includes a Data-Ready-to-Send (DRS) flag that may be setto zero to identify to the PDSN 324 the identity and total number ofpacket services that are dormant, thereby allowing the PDSN 324 toestablish PPP instances 336, 338 and the requisite R-P links between thePDSN 324 and the PCF/BS 326. If a data call is in progress, the MS 318sets the DRS flag to one and requests reconnection or establishment ofthe PPP instance 328, 330 associated with the call. If no call is inprogress, the MS 318 sets the DRS flag to zero and reports the SR_IDsfor all dormant PPP service instances 328, 330 (SR_IDs 1 and 2)associated with the MS 318. The PCF/BS 326 then sends a message to thePDSN 324 that includes the list of SR_IDs and the MS_ID. The PDSN 324establishes two PPP instances 336, 338 and two (the number of SR_IDsreported by the MS 318) R-P connections. The PDSN 324 and the PCF/BS 326then update their respective tables 340, 342. Thus, the list of dormantSR_IDs informs the PDSN 324 how many PPP instances 336, 338 need to beinitiated and also gives the PCF/BS 326 enough information to update itsR-P/SR_ID table 342.

In one embodiment, as shown in FIG. 3C, an MS 366 travels from thevicinity of a first PDSN 354 and associated PCF/BS 362 to the vicinityof a second PDSN 356 and associated PCF/BS 364 and informs the secondPDSN 356 of the number and identities of PPP instances to beestablished. The first PDSN 354 had established two PPP instances asillustrated between the PDSN 354 and the PCF/BS 362, which were dormant(i.e., not being used to transmit traffic channel data). The variousestablished connections and addresses are included in the respectivetables 350, 358 for the PDSN 354 and the PCF/BS 362, respectively. Thenumber (two) of, and identifiers for, two newly required PPP instances372, 374 are advantageously included in the origination messagetransmitted by the MS 366. For simplicity, only one PCF/BS 362, 364 isshown serving each respective PDSN 354, 356, but it would be understoodthat there could be multiple PCF/BSs serving each PDSN 354, 356. Theorigination message advantageously includes a Data-Ready-to-Send (DRS)flag that may be set to zero to identify to the PDSN 356 the identityand total number of packet services that are dormant, thereby allowingthe PDSN 356 to establish PPP instances 372, 374 and the requisite R-Plinks between the PDSN 356 and the PCF/BS 364. If a data call is inprogress, the MS 366 sets the DRS flag to one and requests reconnectionor establishment of the PPP instance associated with the call. If nocall is in progress, the MS 366 sets the DRS flag is set to zero andreports the SR_IDs for all dormant PPP service instances 372, 374(SR_IDs 1 and 2) associated with the MS 366. The PCF/BS 364 then sends amessage to the PDSN 356 from the table 360 storing the R-P IDs, SR_IDsand MS_ID. The PDSN 356 establishes two PPP instances 372, 374 and two(the number of SR_IDs reported by the MS 318) R-P connections. The PDSN356 and the PCF/BS 364 then update their respective tables 352, 360.Thus, the list of dormant SR_IDs informs the PDSN 356 how many PPPinstances to initiate and also gives the PCF/BS 326 enough informationto update its R-P/SR_ID table 352. Note that the table 352 includes theR-P IDs, MS_ID, and IP address.

In one embodiment an MS (not shown) performs the method stepsillustrated in FIG. 4 when leaving the vicinity of a PDSN (also notshown) and entering the vicinity of a neighboring PDSN (also not shown).In step 400 the MS determines whether it is arriving at a new PDSN. Ifthe MS is not arriving at a new PDSN, the MS returns to step 400. If, onthe other hand, the MS is arriving at a new PDSN, the MS proceeds tostep 402. In step 402 the MS determines whether it is engaged in a datacall. If the MS is engaged in a data call, the MS proceeds to step 404.If, on the other hand, the MS is not engaged in a data call, the MSproceeds to step 408.

In step 404 the MS engages in handoff. The MS then proceeds to step 406.In step 406 the MS sends an origination message to the new PDSNinforming the PDSN of its location. A DRS flag in the originationmessage is set to one, and the MS is requesting reconnection orestablishment of a PPP instance associated with the data call. In step408 the MS engages in dormant handoff. The MS then proceeds to step 410.In step 410 the MS sends an origination message to the new PDSNinforming the PDSN of its location. The DRS flag in the originationmessage is set to zero, and the MS includes the number of PPP instancesto establish (the number of dormant PPP instances associated with theMS) and an SR_ID associated with each such PPP instance.

Thus, a novel and improved method and apparatus for requesting PPPinstances from a packet data services network have been described. Thoseof skill in the art would understand that the various illustrativelogical blocks, modules, circuits, and algorithm steps described inconnection with the embodiments disclosed herein may be implemented aselectronic hardware, computer software, or combinations of both. Thevarious illustrative components, blocks, modules, circuits, and stepshave been described generally in terms of their functionality. Whetherthe functionality is implemented as hardware or software depends uponthe particular application and design constraints imposed on the overallsystem. Skilled artisans recognize the interchangeability of hardwareand software under these circumstances, and how best to implement thedescribed functionality for each particular application. As examples,the various illustrative logical blocks, modules, circuits, andalgorithm steps described in connection with the embodiments disclosedherein may be implemented or performed with a digital signal processor(DSP), an application specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA) or other programmable logic device,discrete gate or transistor logic, discrete hardware components such as,e.g., registers and FIFO, a processor executing a set of firmwareinstructions, any conventional programmable software module and aprocessor, or any combination thereof. The processor may advantageouslybe a microprocessor, but in the alternative, the processor may be anyconventional processor, controller, microcontroller, or state machine.The software module could reside in RAM memory, flash memory, ROMmemory, registers, hard disk, a removable disk, a CD-ROM, or any otherform of storage medium known in the art. Those of skill would furtherappreciate that the data, instructions, commands, information, signals,bits, symbols, and chips that may be referenced throughout the abovedescription are advantageously represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Preferred embodiments of the present invention have thus been shown anddescribed. It would be apparent to one of ordinary skill in the art,however, that numerous alterations may be made to the embodiments hereindisclosed without departing from the spirit or scope of the invention.Therefore, the present invention is not to be limited except inaccordance with the following claims.

1. A method of informing a packet data services network of dormantnetwork connections associated with a mobile station when the mobilestation moves from a first packet data service node of the packet dataservices network to a second packet data service node of the packet dataservices network, the method comprising the step of: transmitting fromthe mobile station to the second packet data service node of the packetdata services network a message including a number of dormant networkconnections associated with the mobile station and a list of identifiersassociated with the dormant network connections, wherein the message istransmitted in response to the mobile station moving from the firstpacket data service node to the second packet data service node.
 2. Themethod of claim 1, wherein the dormant network connections comprisepoint-to-point protocol connections.
 3. The method of claim 1, whereinthe identifiers comprise service reference identifiers, wherein eachservice reference identifier is associated with a point-to-pointprotocol instance.
 4. The method of claim 1, wherein the messagecomprises an origination message including an indicator that the dormantnetwork connections are dormant.
 5. The method of claim 1, wherein themessage comprises a data-ready-to-send flag, and further comprising: ifa data call is in progress, setting the data-ready-to-send flag to afirst value and requesting re-establishment of a point-to-point protocolinstance associated with the data call; and setting thedata-ready-to-send flag to a second value if no data call is inprogress.
 6. A mobile station configured to inform a packet dataservices network of dormant network connections associated with themobile station when the mobile station moves from a first packet dataservice node of the packet data services network to a second packet dataservice node of the packet data services network, the mobile stationcomprising: an antenna; a processor coupled to the antenna; and aprocessor-readable medium accessible by the processor and containing aset of instructions executable by the processor to modulate and transmitfrom the mobile station to the second packet data service node of thepacket data services network a message including a number of dormantnetwork connections associated with the mobile station and a list ofidentifiers associated with the dormant network connections, wherein themessage is transmitted in response to the mobile station moving from thefirst packet data service node to the second packet data service node.7. The mobile station of claim 6, wherein the dormant networkconnections comprise point-to-point protocol connections.
 8. The mobilestation of claim 6, wherein the identifiers comprise service referenceidentifiers.
 9. The mobile station of claim 6, wherein the messagecomprises an origination message including an indicator that the dormantnetwork connections are dormant.
 10. A mobile station configured toinform a packet data services network of dormant network connectionsassociated with the mobile station when the mobile station moves from afirst packet data service node of the packet data services network to asecond packet data service node of the packet data services network, themobile station comprising: a device configured to transmit from themobile station to the second packet data service node of the packet,data services network a message including a number of dormant networkconnections associated with the mobile station and a list of identifiersassociated with the dormant network connections, wherein the message istransmitted in response to the mobile station moving from the firstpacket data service node to the second packet data service node.
 11. Themobile station of claim 10, wherein the dormant network connectionscomprise point-to-point protocol connections.
 12. The mobile station ofclaim 10, wherein the identifiers comprise service referenceidentifiers.
 13. The mobile station of claim 10, wherein the messagecomprises an origination message including an indicator that the dormantnetwork connections are dormant.
 14. A mobile station configured toinform a packet data services network of dormant network connectionsassociated with the mobile station when the mobile station moves from afirst packet data service node of the packet data services network to asecond packet data service node of the packet data services network, themobile station comprising: means for establishing network connections;and means for transmitting from the mobile station to the second packetdata service node of the packet data services network a messageincluding a number of dormant network connections associated with themobile station and a list of identifiers associated with the dormantnetwork connections, wherein the message is transmitted in response tothe mobile station moving from the first packet data service node to thesecond packet data service node.
 15. The mobile station of claim 14,wherein the dormant network connections comprise point-to-point protocolconnections.
 16. The mobile station of claim 14, wherein the identifierscomprise service reference identifiers.
 17. The mobile station of claim14, wherein the message comprises an origination message including anindicator that the dormant network connections are dormant.
 18. Anon-transitory processor-readable medium having processor-readableinstructions stored thereon for informing a packet data services networkof dormant network connections associated with a mobile station when themobile station moves from a first packet data service node of the packetdata services network to a second packet data service node of the packetdata services network, the processor-readable medium comprisinginstructions that are executable to: transmit from the mobile station tothe second packet data service node of the packet data services networka message including a number of dormant network connections associatedwith the mobile station and a list of identifiers associated with thedormant network connections, wherein the message is transmitted inresponse to the mobile station moving from the first packet data servicenode to the second packet data service node.
 19. A mobile stationcomprising: circuitry configured to: inform a packet data servicesnetwork of dormant network connections associated with the mobilestation when the mobile station moves from a first packet data servicenode of the packet data services network to a second packet data servicenode of the packet data services network; and transmit a message to thesecond packet data service node of the packet data services network inresponse to the mobile station moving from the first packet data servicenode to the second packet data service node, wherein the messageincluding a number of dormant network connections associated with themobile station and a list of identifiers associated with the dormantnetwork connections.
 20. The mobile station of claim 19 wherein thedormant network connections include point-to-point connections.
 21. Themobile station of claim 19 wherein the identifiers comprise servicereference identifiers, wherein each service reference identifier isassociated with a point-to-point protocol instance.
 22. The mobilestation of claim 19, wherein the message comprises an originationmessage including an indicator that the dormant network connections aredormant.
 23. The mobile station of claim 19 wherein the messagecomprises a data-ready-to-send flag, and wherein if a data call is inprogress, the data-ready-to-send flag is set to a first value, andwherein if no data call is in progress, the data-ready-to-send flag isset to a second value.
 24. A communication apparatus comprising: meansfor informing a packet data services network of dormant networkconnections associated with a mobile station when the mobile stationmoves from a first packet data service node of the packet data servicesnetwork to a second packet data service node of the packet data servicesnetwork; and means for transmitting a message to the second packet dataservice node of the packet data services network in response to themobile station moving from the first packet data service node to thesecond packet data service node, wherein the message including a numberof dormant network connections associated with the mobile station and alist of identifiers associated with the dormant network connections. 25.The communication apparatus of claim 24 wherein the dormant networkconnections include point-to-point connections.
 26. The communicationapparatus of claim 24 wherein the identifiers comprise service referenceidentifiers, wherein each service reference identifier is associatedwith a point-to-point protocol instance.
 27. The communication apparatusof claim 24, wherein the message comprises an origination messageincluding an indicator that the dormant network connections are dormant.28. The communication apparatus of claim 24 wherein the messagecomprises a data-ready-to-send flag, and wherein if a data call is inprogress, the data-ready-to-send flag is set to a first value, andwherein if no data call is in progress, the data-ready-to-send flag isset to a second value.